Dan Cattell, General Atomics' director of army programmes, says "limited" user tests of the aircraft and ground control stations will begin next March, followed by the deployment of four aircraft and two GCS to Iraq in July 2009.

Block 1 Sky Warriors will carry Raytheon's electro-optical/infrared common sensor payload, as originally planned, but will now also be equipped with a Northrop Grumman synthetic aperture radar/ground moving target indication payload, rather than General Atomics' Lynx system. The latter company has built 10 Lynx payloads, eight of which could be made available for Block 0 or Block 1 aircraft, it says.

Six Block 0 aircraft are being built as part of a rapid deployment effort to get the Sky Warrior into combat quickly. The aircraft will carry the Raytheon sensor package, but no SAR system or tactical datalinks. Cattell says efforts are underway to gain Congressional plus-up funding to install the Lynx the aircraft, however. Two Block 0 aircraft have been completed to date, with the first delivered unit scheduled to fly in Iraq for the first time on 15 April.

Included in the roll-out of both aircraft is additional training for operators, as the Sky Warrior is heavier than legacy Predators, with more wing area and a wing flap system, says Cattell.

Block 1 aircraft will also have redundant automatic landing capabilities using triple redundant differential GPS horizontal positioning, calculated by a Honeywell navigation system and two Athena Technologies systems, and vertical positioning determined by three laser altimeters. A millimetre-wave radar will provide back-up in case of GPS jamming, with a receiver and transmitter on the aircraft and two microwave dishes on the ground.